The present invention relates to writing instruments of the ball point type and more particularly to a ball point member for use in a ball point pen and the method of manufacturing the same.
Various ball point pens are manufactured and marketed which have met with user acceptability and include both the type wherein a replaceable refill element is employed in a permanent outer casing, and those wherein the entire pen is disposable after the ink supply has been used. In either the case where a refill is employed, or the disposable type pen, the structure generally employs a tubular member formed by a thin wall having a spherical ball retained in one end and open at the opposite end for receiving the writing fluid and directing it to the surface of the ball.
In those ball point pens on the market today, the ball and socket extend from the point of the pen and are located on the longitudinal axis of the point or refill tube providing the greatest exposure of the ball surface in a plane at right angles to the axis of the pen. It would therefore follow that the best performance could be obtained from the instrument by the user orienting the pen casing at right angles to the writing surface during usage of the pen. However, this is generally not the orientation which is assumed by the user, as a more comfortable writing position is obtained with the pen oriented at an angle to the writing surface. It has been observed that some people write at such a low angle that the rim of the ball socket is caused to touch the paper while writing, which may cause skipping, or a rough feel. Thus, the optimum performance of the ball is not obtained, which may cause a skipping in the line of writing, or a change in line thickness or quality during the employment of the pen.
To overcome the above inadequacy, it has been suggested to bend the pen point such that the ball will be exposed at its maximum area while the user employs the pen at a comfortable angle relative to the writing surface. However, placing a bend in the relatively thin walled tube of the point or refill presents a problem in that the wall, which may be as thin as ten thousandths of an inch is easily stretched beyond the breaking point during the bending operation. Additionally, the stretching of the tube material may effect the wall at the socket where the ball is retained. A variance of one or two ten thousandths of an inch in accuracy at the ball and socket would in many instances cause the pen to fail to write, skip, be starved of ink or produce a blob of ink on the writing surface.
It is therefore an object of the present invention to provide a method of manufacturing a ball point pen member for use in a ball point pen wherein the tubular body member is bent without damage to the ball and socket of the pen.
A further object of the invention is to provide a method of manufacturing a ball point member wherein the pen point is bent without employment of expensive tooling and can be performed on existing pen making equipment.
Yet another object of the invention is to provide a method of manufacturing a ball point member for use in a ball point pen wherein the tubular body member is bent to an angle of at least 30.degree. without destroying the integrity, or degrading the quality of the ball point member.